冠突散囊菌发酵对2种新工艺茶叶成分及活性的影响

Effects of Eurotium cristatum on chemical compositions and activities of the new process teas

8730和金花香橼是2种以冠突散囊菌为优势菌发酵的新工艺茶叶,其原料分别为黑毛茶和高火烘焙的乌龙茶。为考察冠突散囊菌发酵对2种茶叶成分和活性的影响,以8730和金花香橼的原料、过程样及成品为试验材料,测定茶多糖、还原糖、咖啡碱、茶多酚(儿茶素类)、茶黄素和总黄酮的含量。在此基础上,对样品的抗氧化能力、α-葡萄糖苷酶抑制能力及α-淀粉酶抑制能力进行测定。结果表明,随发酵进程的加深,茶多糖含量先下降,之后显著上升;咖啡碱、茶黄素、儿茶素类成分及总黄酮含量总体呈现出下降趋势;8730成品茶叶中的表儿茶素(EC)、没食子酸儿茶素(EGC)含量略高于金花香橼成品,前者中的儿茶素(C)、表儿茶素没食子酸(ECG)略低于后者,表没食子儿茶素没食子酸酯(EGCG)含量两者差异不大(分别为3.23 mg/g和3.42 mg/g)。8730和金花香橼由原料制备成成品,抗氧化性无显著变化。在特定浓度范围内,金花香橼抑制α-葡萄糖苷酶和α-淀粉酶的能力均强于8730,与其高火烘焙工艺相关;反之,8730促进淀粉消化的作用更强。因此,以高火烘焙的乌龙茶为原料,利用冠突散囊菌发酵制备茶叶,与传统茯砖茶相比,由于减缓淀粉消化速率,可能有助于增强其代谢健康益处;同时由于酯型儿茶素显著下降,茶叶对胃肠道的刺激性降低,有助于提高饮茶者的耐受性。

8730 and Jinhua Xiangyuan were produced by the new process using Eurotium cristatum. This study was brought to inspect the influence of Eurotium cristatum on the new process teas and the impact which fungus growing bring to the raw materials and activities. The major changes of tea polysaccharide, caffeine, tea polyphenols, theaflavins, flavonoids, antioxidant activity and the inhibition rate of α-glucosidase and α-amylase were brought to evaluate the variation in 8730 and Jinhua Xiangyuan. The results showed that, the content of caffeine, theaflavins, catechin and flavonoids decreased during the process of fermentation, while the content of tea polysaccharide decreased firstly and then increased. After fermentation, the content of epicatechin(EC) and epigallocatechin(EGC) were higher in 8730 than those in Jinhua Xiangyuan. Epigallocatechin gallate was the same in these two samples(3.23 mg/g, 3.42 mg/g respectively). The antioxidant activity showed no significant change in the raw material and the product of 8730 and Jinhua Xiangyuan. The inhibition of α-glucosidase and α-amylase of Jinhua Xiangyuan was stronger than that of 8730 in the range of specific concentration, mainly because of the process of baking in high temperature. On the contrary, the function of promoting the digestion of starch was high in 8730 than Jinhua Xiangyuan. Therefore, tea which were made from oolong tea with the process of high temperature baking and fermentation using Eurotium cristatum could contribute to the improvement of its metabolic health benefits by slowing down the digestion rate of starch. At the same time, the irritation of tea to the gastrointestinal tract was reduced because of the signification decrease of ester catechins, which was helpful to improve the tolerance of consumers.